Typically, optoelectric conversion elements such as a CCD (Charge Coupled Devices) sensor, a CMOS (Complementary Metal Oxide Semiconductor) sensor and the like are widely known as imaging elements adapted to capture an image. In recent years, a combination of a thin film transistor (hereinafter abbreviated as “TFT”), capacitor and other components has been proposed to function as an optoelectric conversion element. An example thereof is, for example, a display device which includes liquid crystal display elements, the TFT adapted to function as an optoelectric conversion element and other components in each of pixels arranged in a matrix. The display device further includes a backlight or frontlight as a light source and displays an image by transmitting light from the light source through the liquid crystal display elements. On the other hand, the display device permits entry of information using incident light onto the TFT (refer, for example, to Japanese Patent Laid-Open No. 2002-268615). The display device configured as described above allows for image display and information entry on the same screen region. Therefore, such a display device is expected to find application as an information input/output device to replace a touch panel and other devices.
Incidentally, if the TFTs or other components adapted to function as optoelectric conversion elements are arranged in a matrix, driver circuits as shown, for example, in FIG. 10, are required to control the driving of each of the TFTs or other components. That is, a reset driver 112, read driver 113 and source voltage driver 114 need to be provided for a sensor group 111, in which TFTs or other components are arranged in a matrix, as vertical drivers disposed along the vertical direction of the matrix. The reset driver 112 resets the charge stored condition of the sensor group 111. The read driver 113 reads out the stored charge. The source voltage driver 114 controls the applied voltage. Further, a horizontal driver 115 is also required along the horizontal direction of the matrix. Of these drivers, the reset driver 112 includes shift registers to be associated with the lines in the matrix arrangement as illustrated in FIG. 11. The reset driver 112 sequentially performs a reset operation on each of the lines in response to a reset signal (ResetVST) from a higher-level circuit (not shown) as a trigger. Also, similarly, the read driver 113 sequentially performs a signal read out operation from each of the lines in response to a read signal (ReadVST) from the higher-level circuit as a trigger. Then, as illustrated in FIG. 12, after the reset operation is performed sequentially by the reset driver 112 on each of the lines of the sensor group 111 in response to the reset signal (ResetVST), the read driver 113 sequentially performs a signal read out operation upon receipt of the read signal (ReadVST) to read out the charge stored in the sensor group 111 after the reset.
However, the above-mentioned conventional driver circuit configuration requires the plurality of driver circuits 112, 113 and so on as vertical drivers. Therefore, the configuration is not preferred for the following reasons. That is, the plurality of driver circuits 112, 113 and so on require a large layout space. This may lead to a larger so-called frame region around the effective screen region. Further, the plurality of driver circuits 112, 113 and so on lead to more wirings. This may make it difficult to secure an opening area in each pixel. Further, for example, if the plurality of driver circuits 112, 113 and so on are disposed on one side of the sensor group 111, there is a need to provide wirings so that the wirings straddle at least one of the driver circuits. This may result in extremely low layout efficiency.
In light of the foregoing, it is an object of the present invention to provide an imaging device capable of realizing a driver configuration which does not require much layout space, ensures a reduced number of wirings and prevents wirings from straddling any of the driver circuits, and a driving method of the same, display device and electronic apparatus.